Greek authorities are reporting 15 cars burned overnight at three Italian automobile dealerships in Athens and two bombs set off outside bank offices in the northern city of Salonika.

Officials attribute the attacks to anarchist groups, noting an increase in their activity in recent weeks. They say cars were destroyed at three Fiat dealerships and among vehicles parked nearby. One of the parked vehicles was the property of the Greek Orthodox Church.

In Salonika, attackers threw gas canisters at two offices of the private Eurobank, damaging their entrances. No injuries were reported in those incidents.

Earlier, about 20 youths attacked two police officers Thursday, getting away with a handgun. The Associated Press says one of the officers was hospitalized.